There is nothing in the manifested universe which does not possess an energy form, subtle and intangible yet substantial, which controls, governs, and conditions the physical. With reference to the physical body, it is termed the etheric body. This energy form is itself conditioned and governed by the dominant solar or planetary energy which ceaselessly creates it, changes and qualifies it.

The etheric body, in the vast majority of humans, is the vehicle or the instrument of astral energy. The mass of humanity are still Atlantean or astral in their nature. The etheric body is composed of interlocking and circulating lines of force emanating from the many levels of consciousness of our planetary life. These lines of energy and this closely interlocking system of streams of force are related to seven focal points or centers to be found within the etheric body. Each of these centers are related to certain types of incoming energy. When the energy reaching the etheric body is not related to a particular center, that center remains passive; when it is related and the center is sensitive to its impact, then that center becomes vibrant and receptive and develops as a controlling factor in the life of the man on the physical plane.

The dense physical body is held together by and is expressive of the energies which compose the etheric body. These energies appear to be of two types: the energies which form, through interlocked lines, the underlying etheric body, as whole and in relation to all physical forms. This form is qualified then by the general life and vitality of the plane on which the Dweller in the body functions, and therefore where his consciousness is normally focused. Another type of energy is the particular energies by which the individual consciously chooses to govern his daily activities. As attitude, attainment and comprehension shift to higher levels, the etheric body will be constantly changing and responding to newer energies.

The etheric body interpenetrates, underlies, and occupies the entire physical organism. It extends beyond the physical form and surrounds it like an aura. According to the point in evolution will be the area which the etheric body covers beyond the outside of the physical body. It may extend for a few or many inches.
Within the physical body, the network of the etheric body is to be found permeating every single part. It is particularly associated at this time with the nervous system, which is fed, nourished, controlled and galvanized by its etheric counterpart. This counterpart is present in millions of tiny streams or lines of energy, to which the Eastern occultist has given the name “nadis”. These nadis are the carriers of energy. They are in fact the energy itself and carry the quality of energy from some area of consciousness in which the Dweller in the body may happen to be focused. According to the state of consciousness and the psychic state of awareness, so will be the type of energy carried by the nadis, passing from them to the outer nervous system.

It must always be remembered that the seven energy centers are not within the dense physical body. They exist only in etheric matter and in the etheric so-called aura, outside the physical body. They are closely related to the dense physical body by the network of nadis. Five of the centers are to be found in the etheric counterpart of the spinal column, and the energy passes through the spinal vertebrae and circulates then throughout the etheric body as it is interiorly active within the physical vehicle. Three head centers exist, one just above the top of the head, another just in front of the eyes and forehead, and the third at the back of the head, just above where the spinal column ends. In practice, the center at the back of the head is not counted in the initiation process, any more than is the spleen, so we have then seven centers to examine.
The powerful effect of the inflow of energy, via the energy body, has itself automatically created these centers or reservoirs of force; the effect of these seven centers upon the physical body in due time produces condensation or a state of what is called “”attracted response” from dense matter, and thus the seven major sets of endocrine glands slowly came into functioning activity.
The whole development of the etheric body falls into two historical stages. The first stage is that in which the etheric energy, flowing thorough responsive centers and creating endocrine glands as a consequence, gradually begin to have a definite effect upon the blood stream; the energy worked through that medium solely for a very long time. This still remains true, for the life aspect of energy animates the blood, through the medium of the centers and their agents, the glands. Hence the words in the Bible that “the blood is the life”. Secondly, as the race of men developed, and consciousness grew greater and certain great expansions took place, the centers began to extend their usefulness and to use the nadis, and thus to work upon and through the nervous system; this produced conscious and planned activity upon the physical plane.
The energy tubules, or nadis, pass to certain areas of the body in three ways:

1. Through the seven major centers through the twenty-one minor centers
2. Through 49 focal points scattered all over the body
3. The physical body, therefore, is triple in design. There is the etheric body, the nadi system and the dense physical body.